Giving air to earthworms and termites

Addressing the topic of ‘Increasing N-use efficiency in CTF’, Mr Knight was quick to point out there was more available soil nitrogen (N) and more ammonium nitrogen in a CTF system than a conventionally-cropped system.

While the subject matter was not well researched, he said there had been demonstrable data obtained from trial work by his company.

“On the South Coast, earthworms are the major contributor to what we have found is a 50 to 60 per cent increase in available nitrogen from CTF systems,” Mr Knight said.

“Termites also are great contributors in other parts of the Wheatbelt.”

According to Mr Knight, earthworms can produce castings equivalent to their own weight, every day.

“So 100 earthworms in a square metre can produce the equivalent of 10 units of N,” he said.

“Typically, earthworm castings have a high N concentration than surrounding soil.”

Earthworms are known also to increase nitrogen mineralisation through a direct and indirect symbiotic relationships with the microbial community (Mycorrhiza).

Termites also can show nitrogen conversion efficiencies exceeding 100pc.

“In South Coast trials, we have seen earthworm tunnelling dramatically reduced in compacted soils,” Mr Knight said.

“In contract on one farm using a CTF system, there were an estimated 10.4 million earthworms a hectare or 1040 a square metre, producing an equivalent 104 kilograms a hectare of N.”

Of course the context of Mr Knight’s talk related to a well-balanced farming system with a focus on diversity and enhancing soil, particularly with oxygen.

“A lot of compacted soils are depleted of oxygen,” he said.

“Deep ripping helps to re-introduce oxygen and plant available oxygen is helping to reduce wide scale water-logging and soil biology returns (along with earthworms and termites).

“There’s an old adage that goes – look after Mother Nature and she’ll look after you.”